Case Studies from the Dinaric Karst of Slovenia

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Fig. 26: Fatničko polje (Fatnica polje) in the eastern Herzegovina (DEM source: ASTER GDEM 1”; figure made by: A. Mihevc).sion dolines that form due to locally strongercorrosion. Suffusion dolines form primarily atthe edges of karst poljes due to the washing ofsediments. Some dolines are collapse dolines.Larger features of the Dinaric karst include uvalasand karst poljes.PoljesKarst poljes are the largest flat-floored encloseddepressions in karst (Fig. 26). They differfrom other closed depressions in size and theirlarge flat bottoms which formed as baselevelcorrosion plains. Typical forms have a sinkingriver, steep slopes and a sharp transition betweenthe polje floors and slopes. The bottomof the polje may be covered by sediments.There are about 130 poljes in the Dinaric karst(Gams 1978); about 44 of them are recognizedas outstanding (Fig. 25).Gams (1978) defined some criteria thatmust be met for a depression to be classifiedas a polje. These include a flat floor in the rockor in unconsolidated sediments such as alluvium,a closed basin with steeply rising marginalslope on at least one side, and karstic drainage.Three basic types of poljes have been defined:border poljes, structural poljes andbaselevel poljes (Ford & Williams 2007).Border poljes develop where water tablefluctuations in karst control allogenic fluvialactivity at the surface, so lateral planationdominates valley incision.35
Structural poljes are dominated by bedrockgeological controls. This type of poljes prevailson the Dinaric karst. They are connected withgraben or overthrust structures, or as inliers ofless karstified rocks like dolomite, marl or evenflysch.Baselevel poljes occur where dissolutionhas lowered the karst surface to the regionalepiphreatic zone. Typically these poljes developin lower parts of the karst, but they alsooccur in higher parts of the Dinaric mountainswhere impermeable formations may act as hydrologicalbarriers.Dinaric poljes are polygenetic features.They are generally elongated along the strikeof the Dinarsko gorovje (i.e. in a northwest—southeast direction). Poljes are developed atall elevations, between 1,200 and 20 m abovesea level. A complex suite of processes governstheir genesis. They develop along regionalfaults, graben structures and overthrust. Thehighest is Trebistovo polje, (1,278 m a.s.l.) andthe lowest are Bokanjačko polje and Vrgoračkojezero (Vrgorac lake; only 20–25 m a.s.l.).The largest poljes are Liško polje (460 km 2 )and Livanjsko Polje (65 km long and 6 km,402 km 2 ), but the majority of poljes are smaller,covering only few 10 km 2 .In natural conditions floods are normalphenomena for many poljes. In some poljeslike Cerkniško polje and Buško blato they lastedabout half a year. The flooding of 60 kmlong Popovo polje under natural conditionsreached a height of 40 m in the lowest sectionof the polje, and the average yearly flood durationwas 253 days.Poljes are very important for human settlement.In them the best, and often only, arableland in the Dinaric karst is available. There isalways some water available and floods areregular and limited to lower parts of poljes, soall of the largest settlements are located there.Fig. 27: Klekovača and Materniča uvala are two large closed depressions northern of Livanjsko polje in Bosnia. Note that thebottom of large uvala is dotted with dolines (DEM source: ASTER GDEM 1”, figure made by: A. Mihevc).36
Page 2 and 3: Andrej Mihevc, Mitja Prelovšek, Na
Page 4 and 5: ContentsGeographical Position and G
Page 7 and 8: Fig. 2: Coastal part of Dinaric kar
Page 9 and 10: ogy started. In 1531 a lawyer from
Page 11 and 12: include numerous data and general o
Page 13 and 14: GeologyNadja Zupan HajnaThe Dinaric
Page 15 and 16: ceous. The final disintegration of
Page 17 and 18: Fig. 11: Locations of Jelar Breccia
Page 19 and 20: ClimateMitja PrelovšekThe Dinaric
Page 21 and 22: 311 mm/a; Zaninović 2008) and incr
Page 23 and 24: 24Fig. 16: Spatial distribution of
Page 25 and 26: ocks (such as Eocene flysch, Lower
Page 27 and 28: absent. Downstreamparts of the cany
Page 29 and 30: GeomorphologyAndrej MihevcIn folk l
Page 31 and 32: long. They are smoother especially
Page 33: is now depositing. Best known are t
Page 37 and 38: Fig. 28: Typical dolines of Dinaric
Page 39 and 40: the disintegrated collapsed rock at
Page 41 and 42: on Northern Velebit, where three ca
Page 43 and 44: Land UseNadja Zupan Hajna, Andrej M
Page 45 and 46: for ‘bare limestone desert’ -th
Page 47 and 48: Fig. 38: Grančarevo dam in the upp
Page 49 and 50: KrasThe Kras is a distinct plateau,
Page 51 and 52: in this part of the Kras (Mihevc 20
Page 53 and 54: dolomite barrier along the Idrija w
Page 55 and 56: of Dolenjska (Gams, 1974; Kranjc, 1
Page 57 and 58: Fig. 44: Blind valleys of Matarsko
Page 59 and 60: ly several dozen meters deep. Shaft
Page 61 and 62: smaller than the higher ones. The r
Page 63 and 64: tion in the Divaški kras (Mihevc 1
Page 65 and 66: Use of Karst and its ProtectionThe
Page 67 and 68: Gams, I., Vrišer, I. (Eds.), 1998:
Page 69 and 70: lems.- Dela 38, Raziskovalni center

Case Studies from the Dinaric Karst of Slovenia

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